One form of contraception involves the occlusion of reproductive tracts, particularly, the Fallopian tubes in female subjects and the vas deferens in male subjects, with an embolic material and/or occluding device that acutely and/or chronically (following foreign body tissue reaction or epithelialization) blocks passage of sperm through the reproductive tract. Particular forms of occluding devices and systems and methods of inserting the occluding devices in the vas deferens or Fallopian tubes are described in commonly owned U.S. Pat. Nos. 6,096,052 and 6,432,116 and in commonly assigned U.S Patent Application Publication Nos. 2001/0041900, 2005/0045183, 2005/0085844, 2005/0192616, 2005/0209633, and 2006/0009798, for example, certain features of which are embodied in the Ovion™ permanent contraceptive system sold by the assignee of the present invention. Further occluding devices and systems and methods for disclosing the occluding devices in Fallopian tubes are disclosed in U.S. Pat. Nos. 6,763,833 and 6,709,667, for example.
The transvaginal and transcervical advance of the occluding device delivery catheter to dispose the occluding device in a selected Fallopian tube is aided through the use of an endoscope or hysteroscope that illuminates and provides visualization of the uterine cavity and the ostia of the Fallopian tubes. A particularly desirable flexible hysteroscope is disclosed in commonly assigned U.S Patent Application Publication Nos. 2005/0288551 that is employed to guide an occluding device installation catheter through the uterine cavity and into selected ostium of a selected Fallopian tube under such visualization.
In practice, an occluding device is assembled to the occluding device delivery catheter, and the assembly is advanced through a lumen of the hysteroscope. The hysteroscope is advanced through the transvaginal and transcervical path as the path is visualized to locate a Fallopian tube ostium and to direct the distal end of the delivery catheter into the Fallopian tube. In one approach, the occluding device is then released into the Fallopian tube by expelling the contracted occluding device from the catheter lumen, which self expands when released, enabling withdrawal of the delivery catheter. In another approach, a catheter-borne deflated balloon that the contracted occluding device is mounted to is expanded at the delivery site to thereby expand the occluding device against the Fallopian tube wall. The balloon is then deflated to enable withdrawal of the delivery catheter. The occluding device delivery process is followed to sequentially dispose one occluding device in the right Fallopian tube and another occluding device in the left Fallopian tube.
The occluding devices inserted into the Fallopian tubes employing the Ovion™ permanent contraceptive system are relatively short in length (in contrast to those disclosed in the above-referenced '833 and '677 patents) order to be as unobtrusive as possible and to avoid intruding into the uterine cavity. These occluding devices are delivered so deeply into the Fallopian tube as to be invisible from inspection of the uterine cavity employing the hysteroscope. Thus, there is no visible indication within the uterine cavity as to whether an initially installed occluding device is installed in the right or left Fallopian tube. Consequently, there is a possibility that the implanting physician may become disoriented when advancing the delivery catheter and hysteroscope within the uterine cavity and erroneously install the second occluding device into the same Fallopian tube that the first occluding device was installed into. If uncertainty arises, it may be necessary to interrupt the procedure to employ external fluoroscopy or other imaging equipment to pinpoint the location of the first installed occluding device.
Accordingly, it would be desirable to provide a way to ensure that the physician does not mistakenly install a second occluding device of the type that does not extend into the uterine cavity when installed into the same Fallopian tube that the first occluding device is installed into. It would also be desirable to mark the location of any such occluding device occluding a reproductive tract.